In the field of automotive vehicles, it has become popular to employ steering column assemblies that include tilt (“rake”) and/or telescoping (“reach”) functions. Assemblies that employ both tilt and telescoping functions are known also as “rake and reach steering column assemblies.” The use of motors to translate a steering wheel relative to a vehicle operator also has seen increased use. It is common to employ motors to perform one or both of the tilt and telescoping functions. For example, one motor may be operated to actuate the steering column assembly generally in an upward or downward vertical direction to adjust the height of a steering wheel relative to an operator of the vehicle and thus perform the tilt function. Another motor may be operated to actuate the steering column assembly to adjust the fore/aft position of the steering wheel relative to the vehicle operator. The latter typically achieves the adjustment by way of translation of a telescopic tubing arrangement by which at least one inner tube associated with the steering wheel translates relative to a shaft for steering.
It also has become more prevalent to employ steering column assemblies that are adapted to mount to a vehicle structure by use of a bracket structure, which may include one or more bracket components, and (in turn) which may be pivotally connected (e.g., at or near its forward end) to a column housing that receives an inner tube. This is a particularly attractive arrangement for use with internally collapsing column assemblies. Such assemblies may employ a bracket structure adapted to affix the assembly to a vehicle structure. A tilt and/or telescope assembly may be pivotally connected to the bracket structure. For instance, it may be connected at or proximate (e.g., within about 50 millimeters, or possibly within about one third of the length of the steering column assembly in its fully telescoped position) a forward end of the assembly, or elsewhere along the length of the assembly. Due to the fact that steering column assemblies are relatively large assemblies, especially when the pivotal connection is at or proximate the forward end, even small differences in dimensional tolerances (e.g., at the pivotal connection location) can result in a relatively large lash effect for the vehicle operator. That is, dimensional tolerance differences from vehicle to vehicle may lead to the potential for some vehicle operators to sense side to side motion of the steering column during steering column adjustment, or possibly even when steering.
One approach proposed to address this phenomena has been the use of a constant thickness side plate that is mounted to a bracket structure (e.g., at a side wall of a bracket structure, such as a top bracket) so that the plate is positioned between the side wall of the top bracket and the column housing. The side wall of the top bracket is generally parallel with the axis of vertical translation of the column working during a tilt adjustment. During installation, the side plate is fitted in a gap between the top bracket and the column housing and is fastened to the top bracket with two or more vertically spaced fasteners. Much trial and error is required during assembly to determine the proper location and position of the side plate so that it will engage the column housing during tilt adjustment, resist lash and not result in too much noise generation from a tilt adjustment motor working to overcome opposing forces as the column housing rubs against the plate during tilt adjustment. This is particularly the case in view of the potential for manufacturing inconsistencies of components, some of which are cast articles and may require one or more machining or finishing steps. To illustrate this approach, reference is made to FIGS. 1A and 1B, which show a portion of a steering column assembly 10, including a top bracket 12 adapted to be pivotally connected to a column housing (not shown) at a forward end 14. The top bracket 12 generally has a planar upper surface 16, and includes a side wall 18 that is perpendicular to the plane of the upper surface. A spacer plate 20 having a forward surface 22 and a parallel rearward surface 24 is located in a space between the top bracket 12 and the column housing. The spacer plate 20 is connected to the side wall 18 of the top bracket 12 by a pair of vertically spaced fastener connectors 26a and 26b that are adapted to be individually adjustable for allowing the spacer plate 20 to be secured to the side wall 18 and adjusted through a series of trial and error adjustments for realizing the appropriate location and spacing of the spacer plate relative to the side wall, while also causing the spacer plate to bear against the column housing for resisting lash over a range of tilt adjustment locations.
As can be appreciated, there are expected to be differing dimensional tolerances from one assembly to another. Further, depending upon the location of the spacer plate relative to the side wall, there may result undesirable noise from an adjustment motor working to overcome opposing forces arising from the column assembly bearing against the spacer plate during tilt adjustment. As a result of the above, it is seen how assembly operations can be potentially complicated and not as efficient as may be desired.
There is a need for an alternative assembly and method of making the assembly that will help to reduce steering column lash effects, that will generate relatively little noise when the tilt function of a steering column assembly is employed, that will apply suitable force to help resist transverse translation of the steering column assembly once an adjustment has been made, that will provide for relatively efficient assembly operations, or any combination thereof.